For fruit, red and black currants are preferred over alpine or golden.

Jostaberry is a fast-growing hybrid between the black current and gooseberry.

Red currants (Ribes sativum and R. rubrum), black currents (R. nigrum) gooseberries (R. grossularia svn. R. uva-crispa) and jostaberries (R. nidigrolaria) have ornamental as well as fruit value. Their hardiness and adaptability allow them to succeed where most other fruit crops fail. With proper variety selection and care, currants, gooseberries and jostaberries may be grown at elevations up to 10,000 feet.

Varieties

Red and black currants are preferred for fruit production over alpine or golden currants. Red Lake produces a dark red, mild, subacid berry averaging 3/8 inch. It is the most popular variety carried by local nurseries and is recommended for Colorado. Wilder, a similar variety but with larger clusters, also is recommended. White and pink currents are also available. Both are red currents selected for their pale fruit color. Zante currants are actually dried grapes (raisins); do not confuse them with currants.

Gooseberries recommended for Colorado are Pixwell and Welcome. Pixwell produces round 1/2-inch berries that are light green, maturing to a soft pink. Welcome, sweeter and darker at maturity, also produces a 1/2-inch berry. Its thorns are not as numerous or stiff as Pixwell, making it easier to pick. Other varieties that may be of interest to Colorado gardeners are Hinnomaki Red, which produces small, dark red berries with good flavor, and Invicta, which produces very large, pear-shaped berries with excellent flavor.

Jostaberries are a hybrid between the gooseberry and the black current. Berries are two to three times the size of the red current, nearly the size of the common gooseberry. They are nearly black, although more reddish forms are available. Best fruit set occurs when both black and red jostaberries are grown.

Both currants and gooseberries are self-fruitful, meaning only one variety is needed for fruiting. However, having more than one plant and plants of different varieties may increase yields.

Location and Soil

Currants, gooseberries and jostaberries grow best in full sunlight but do tolerate partial shade. For large scale production growers should provide a windbreak. Otherwise, drying winds may reduce plant growth and fruit size.

They produce best in fertile, loamy, well-drained soils with a pH of 6 to 7. However, they will tolerate clay soils with higher a pH and because they produce some fruit even in poor soils, they can serve as ornamentals that attract wildlife in areas receiving infrequent watering.

A soil test is best for determining fertility levels. However, in lieu of a soil test, the following recommendations are made. If planted in good garden soil, the plants need only a maintenance amount of fertilizer— 4 pounds of ammonium sulfate and 2 pounds of treble superphosphate per 1,000 square feet. However, if the soil has not produced a good garden, apply 8 pounds of ammonium sulfate, 4 pounds of treble superphosphate, 1 pound of zinc sulfate and 1 pound of iron chelate per 1,000 square feet. For smaller plantings 4-8 ounces of a 10-10-10 fertilizer should be applied per plant per year.

For new plantings it may be beneficial to incorporate 3 yards (approximately 1 inch) of manure or manure based compost or 6-9 yards (2-3 inches) of plant based compost into the top 6-8 inches of soil per 1,000 square ft.

Planting

Red currants and gooseberries are propagated from cuttings of year-old wood or through mound layering. They generally are sold as one- or two-year old bare-root plants. Local nurseries carry them growing in containers as two- or three-year-old plants.

Plant them 3.5 to 4.5 feet apart in early spring, in rows spaced 6 to 8 feet apart. Prior to planting, prune out all damaged roots and branches of bare-root stock. Cut branches back to 5 inches, and set plants 1 to 2 inches below the soil line. Water well.

Care and Maintenance

Control weeds to reduce competition and increase yield. These shrubs respond well to a heavy mulch of straw or similar material. When using straw, apply nitrogen at the rate of one part per 100 parts of dry matter. Mulch reduces weeds, water needs, and winter injury to roots caused by alternate freezing and thawing.

Apply adequate irrigation for best fruit size and yield. After harvest, gradually reduce the amount of water to harden the plants prior to winter. Give a final watering in November to reduce drying during the winter.

Pruning

Pruning is required for good yield. Red currants and jostaberies bear fruit on spurs (shortened fruiting branches) of two- and three-year-old wood. Some fruit is borne near the base of year-old wood. Gooseberries are similar, but their year-old wood is more fruitful.

Prune in late winter or early spring prior to bud swelling. Remove wood more than three years old, and thin out younger wood. The resulting bush should have three upright canes each of three-, two- and one-year-old wood. Gooseberries sometimes are pruned to remove more of the three-year-old wood while retaining more younger wood. See Figure 1.

Figure 1: Currant showing correct pruning of mature shrub. Numbers 1, 2 and 3 indicate age of stem in years.

Insects and Diseases

A wide range of insects and diseases affect currants, gooseberries and jostaberries. To avoid problems, purchase only quality, disease-free plants.

Insects most commonly observed are aphids, cane borers and red spider mites. Aphids are small, soft-bodied, pear-shaped insects on the underside of leaves.

Caneborers are small white grubs that bore into stems, causing wilting of the upper portion of the cane. Control them by pruning well below the wilted tip and destroying the affected part.

Red spider mites are hard to see because they are so small. Look for yellow spots on the leaves that eventually turn brown.

Although diseases are common to currants, gooseberries and jostaberries in other areas, they have not yet been reported as major problems in Colorado.

Harvesting and Preservation

Red currants are borne in clusters and generally are deep red and soft when fully ripe. Pick currants by pinching off the main cluster stem at the base, using the forefinger and thumb. For jelly, pick them slightly underripe when the pectin level is high. For juices, jams and tarts, pick them when fully ripe and soft. Picking may last two or three weeks, as they remain useable for some time while on the bush. Currants may be dried and used as a substitute for raisins.

Gooseberries often are picked green, after they reach their full size but before they ripen. Avoid the thorns when picking. Use them within a few days after picking. Use immature gooseberries in pies, tarts, jams and meat sauces. Fully ripe fruit, soft and pink or red, makes an excellent fresh, sweet fruit.

Pick jostaberries when they are fully colored (reddish-black to black) and soft. Harvest time is not critical — berries have a long shelf-life. They make excellent preserves, considered by some to be better than either red currant or gooseberry.

Fruit yield for currants and gooseberries may be 4 to 8 quarts from mature plants, which remain productive up to 20 years.